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////////////////////////////////////////////////////////////////////////////// 
// 
//	Simple Crypt Base Class 
// 
////////////////////////////////////////////////////////////////////////////// 
 
#include "stdafx.h" 
 
CMsgCrypt	g_Crypt; 
 
CSimpleCrypt::CSimpleCrypt() 
{ 
	m_ConstKey1 = 4231234;			//05 - 3 -16 : 032 ΌφΑ€ 	       
	m_ConstKey2 = 2423523;		       
	m_DynamicKey = 14231234;	 
 
//	m_ConstKey1 = 8404211; // Αί±Ή 
//	m_ConstKey2 = 2298201; 
//	m_DynamicKey = 19071510; 
 
//	m_ConstKey1 = 2366183; 
//	m_ConstKey2 = 1432754; 
//	m_DynamicKey = 79984829; 
} 
 
CSimpleCrypt::~CSimpleCrypt() 
{ 
} 
 
void CSimpleCrypt::Encrypt32bit(const char * pSrc, char * pDest) 
{ 
	int DynamicKey = m_DynamicKey; 
 
	for (int i = 0 ; i < 4 ; i++) 
	{ 
		pDest[i] = (char)((BYTE)(pSrc[i]) ^ (DynamicKey >> 4)); 
		DynamicKey = ((BYTE)(pDest[i]) + (DynamicKey*2)) * m_ConstKey1 - m_ConstKey2; 
//		pDest[i] = (char)((BYTE)(pSrc[i]) ^ (DynamicKey >> 8)); 
//		DynamicKey = ((BYTE)(pDest[i]) + DynamicKey) * m_ConstKey1 + m_ConstKey2; 
	} 
} 
 
void CSimpleCrypt::Decrypt32bit(const char * pSrc, char * pDest) 
{ 
	int DynamicKey = m_DynamicKey; 
 
	for (int i = 0 ; i < 4 ; i++) 
	{ 
		pDest[i] = (char)((BYTE)(pSrc[i]) ^ (DynamicKey >> 4)); 
		DynamicKey = ((BYTE)(pSrc[i]) + (DynamicKey*2)) * m_ConstKey1 - m_ConstKey2; 
//		pDest[i] = (char)((BYTE)(pSrc[i]) ^ (DynamicKey >> 8)); 
//		DynamicKey = ((BYTE)(pSrc[i]) + DynamicKey) * m_ConstKey1 + m_ConstKey2; 
	} 
} 
 
void CSimpleCrypt::SetKey(int ConstKey1, int ConstKey2, int DynamicKey) 
{ 
	m_ConstKey1 = ConstKey1; 
	m_ConstKey2 = ConstKey2; 
	m_DynamicKey = DynamicKey; 
} 
 
void CSimpleCrypt::Encrypt(void * pData, int nSize) 
{ 
	char pBufSrc[4], pBufDest[4]; 
	char * p = (char*)pData; 
 
	for(int i = 0 ; i < (int)(nSize / 4) ; i++)  
	{ 
		for(int j = 0 ; j < 4 ; j++)  
		{ 
			pBufSrc[j] = *(p + j); 
		} 
		 
		Encrypt32bit(pBufSrc, pBufDest); 
 
		for(j = 0 ; j < 4 ; j++)  
		{ 
			*(p + j) = pBufDest[j]; 
		} 
 
		p = p + 4; 
	}	 
} 
 
void CSimpleCrypt::Decrypt(void * pData, int nSize) 
{ 
	char pBufSrc[4], pBufDest[4]; 
	char * p = (char*)pData; 
 
	for(int i = 0 ; i < (int)(nSize / 4) ; i++)  
	{ 
		for(int j = 0 ; j < 4 ; j++)  
		{ 
			pBufSrc[j] = *(p + j); 
		} 
		 
		Decrypt32bit(pBufSrc, pBufDest); 
 
		for(j = 0 ; j < 4 ; j++)  
		{ 
			*(p + j) = pBufDest[j]; 
		} 
 
		p = p + 4; 
	}	 
} 
 
 
 
////////////////////////////////////////////////////////////////////////////// 
// 
//	Optimized Crypt Class 
// 
////////////////////////////////////////////////////////////////////////////// 
 
 
CMsgCrypt::CMsgCrypt() 
{ 
	m_iMsgHeaderSize = 4; 
} 
 
CMsgCrypt::~CMsgCrypt() 
{ 
} 
 
void	CMsgCrypt::SetMsgHeaderSize(int MsgHeaderSize) 
{ 
	m_iMsgHeaderSize = MsgHeaderSize; 
} 
 
void	CMsgCrypt::EncryptMsgBody(void * pData, int nSize) 
{ 
	char * pMsgBody = (char *)pData; 
	pMsgBody += m_iMsgHeaderSize; 
	 
	Encrypt(pMsgBody, nSize - m_iMsgHeaderSize); 
} 
 
void	CMsgCrypt::DecryptMsgBody(void * pData, int nSize) 
{ 
	char * pMsgBody = (char *)pData; 
	pMsgBody += m_iMsgHeaderSize; 
	 
	Decrypt(pMsgBody, nSize - m_iMsgHeaderSize); 
}